diff --git a/CHANGELOG b/CHANGELOG
index a67058f7a4..e48b5401df 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Manage invoicing of non-time based products
 * Base invoicing on quantity and price
 * Remove duration fields
 
diff --git a/message.xml b/message.xml
index a783da828d..211012405d 100644
--- a/message.xml
+++ b/message.xml
@@ -9,8 +9,11 @@ this repository contains the full copyright notices and license terms. -->
         <record model="ir.message" id="msg_delete_invoiced_line">
             <field name="text">You cannot delete an invoiced line.</field>
         </record>
-        <record model="ir.message" id="msg_missing_product">
-            <field name="text">There is no product on work "%(work)s".</field>
+        <record model="ir.message" id="msg_product_missing_account_revenue">
+            <field name="text">To invoice work "%(work)s" you must define an account revenue for product "%(product)s".</field>
+        </record>
+        <record model="ir.message" id="msg_missing_account_revenue">
+            <field name="text">To invoice work "%(work)s" you must configure a default account revenue.</field>
         </record>
         <record model="ir.message" id="msg_missing_list_price">
             <field name="text">There is no list price on work "%(work)s".</field>
diff --git a/project.py b/project.py
index c083e4f4ba..11fa826406 100644
--- a/project.py
+++ b/project.py
@@ -15,7 +15,7 @@ from sql.operators import Concat
 from trytond.i18n import gettext
 from trytond.model import ModelSQL, ModelView, fields
 from trytond.pool import PoolMeta
-from trytond.pyson import Eval, Bool, PYSONEncoder
+from trytond.pyson import Eval, Bool, If, Id, PYSONEncoder
 from trytond.pool import Pool
 from trytond.transaction import Transaction
 from trytond.wizard import Wizard, StateAction
@@ -36,8 +36,14 @@ class Effort:
     def _get_quantity_to_invoice_effort(cls, works):
         quantities = {}
         for work in works:
-            if work.progress == 1 and not work.invoice_line:
-                quantities[work.id] = work.effort_hours
+            if (work.progress == 1
+                    and work.list_price
+                    and not work.invoice_line):
+                if work.price_list_hour:
+                    quantity = work.effort_hours
+                else:
+                    quantity = 1
+                quantities[work.id] = work.unit_to_invoice.round(quantity)
         return quantities
 
     @classmethod
@@ -58,9 +64,14 @@ class Effort:
                 invoice_line = id2invoice_lines[work.invoice_line.id]
                 invoice_currency = (invoice_line.invoice.currency
                     if invoice_line.invoice else invoice_line.currency)
-                amounts[work.id] = Currency.compute(invoice_currency,
-                    Decimal(str(work.effort_hours)) * invoice_line.unit_price,
-                    currency)
+                if work.price_list_hour:
+                    amount = (
+                        Decimal(str(work.effort_hours))
+                        * invoice_line.unit_price)
+                else:
+                    amount = invoice_line.unit_price
+                amounts[work.id] = Currency.compute(
+                    invoice_currency, amount, currency)
             else:
                 amounts[work.id] = Decimal(0)
         return amounts
@@ -112,13 +123,19 @@ class Progress:
                     (work.progress or 0)
                     - invoiced_progress.get(work.id, 0.0))
                 if delta > 0:
-                    quantities[work.id] = delta * work.effort_hours
+                    quantity = delta
+                    if work.price_list_hour:
+                        quantity *= work.effort_hours
+                    quantities[work.id] = work.unit_to_invoice.round(quantity)
         return quantities
 
     @property
     def progress_to_invoice(self):
         if self.quantity_to_invoice:
-            return self.quantity_to_invoice / self.effort_hours
+            if self.price_list_hour:
+                return self.quantity_to_invoice / self.effort_hours
+            else:
+                return self.quantity_to_invoice
 
     @classmethod
     def _get_invoiced_amount_progress(cls, works):
@@ -150,8 +167,10 @@ class Progress:
             for work_id, amount in cursor.fetchall():
                 if not isinstance(amount, Decimal):
                     amount = Decimal(str(amount))
-                amounts[work_id] = (
-                    amount * Decimal(str(ids2work[work_id].effort_hours)))
+                work = ids2work[work_id]
+                if work.price_list_hour:
+                    amount *= Decimal(str(work.effort_hours))
+                amounts[work_id] = amount
 
             cursor.execute(*table.join(company,
                     condition=table.company == company.id
@@ -188,6 +207,14 @@ class Timesheet:
         super().__setup__()
         cls.project_invoice_method.selection.append(
             ('timesheet', 'On Timesheet'))
+        cls.product.domain = [
+            cls.product.domain,
+            If(Eval('invoice_method') == 'timesheet',
+                ('default_uom_category', '=', Id('product', 'uom_cat_time')),
+                ()),
+            ]
+        if 'invoice_method' not in cls.product.depends:
+            cls.product.depends.append('invoice_method')
 
     @classmethod
     def _get_quantity_to_invoice_timesheet(cls, works):
@@ -215,7 +242,7 @@ class Timesheet:
             duration = durations[work.id]
             if work.list_price:
                 hours = duration.total_seconds() / 60 / 60
-                quantities[work.id] = hours
+                quantities[work.id] = work.unit_to_invoice.round(hours)
         return quantities
 
     @classmethod
@@ -481,7 +508,8 @@ class Work(Effort, Progress, Timesheet, metaclass=PoolMeta):
         "Return a invoice line for the lines"
         pool = Pool()
         InvoiceLine = pool.get('account.invoice.line')
-        Uom = pool.get('product.uom')
+        AccountConfiguration = pool.get('account.configuration')
+        account_config = AccountConfiguration(1)
 
         quantity = sum(l['quantity'] for l in lines)
         product = key['product']
@@ -489,24 +517,32 @@ class Work(Effort, Progress, Timesheet, metaclass=PoolMeta):
         invoice_line = InvoiceLine()
         invoice_line.type = 'line'
         invoice_line.description = key['description']
-        invoice_line.account = product.account_revenue_used
-        if (key['unit']
-                and key['unit'].category == product.default_uom.category):
-            invoice_line.product = product
-            invoice_line.unit_price = Uom.compute_price(
-                key['unit'], key['unit_price'], product.default_uom)
-            invoice_line.quantity = Uom.compute_qty(
-                key['unit'], quantity, product.default_uom)
-            invoice_line.unit = product.default_uom
+        if product:
+            invoice_line.account = product.account_revenue_used
+            if not invoice_line.account:
+                raise InvoicingError(
+                    gettext(
+                        'project_invoice.msg_product_missing_account_revenue',
+                        work=self.rec_name,
+                        product=product.rec_name))
         else:
-            invoice_line.unit_price = key['unit_price']
-            invoice_line.quantity = quantity
-            invoice_line.unit = key['unit']
+            invoice_line.account = account_config.get_multivalue(
+                'default_category_account_revenue')
+            if not invoice_line.account:
+                raise InvoicingError(
+                    gettext('project_invoice.msg_missing_account_revenue',
+                        work=self.rec_name))
+        invoice_line.product = product
+        invoice_line.unit_price = key['unit_price']
+        invoice_line.quantity = quantity
+        invoice_line.unit = key['unit']
 
         taxes = []
         pattern = invoice_line._get_tax_rule_pattern()
         party = invoice.party
-        for tax in product.customer_taxes_used:
+        original_taxes = (
+            product.customer_taxes_used if product else invoice.account.taxes)
+        for tax in original_taxes:
             if party.customer_tax_rule:
                 tax_ids = party.customer_tax_rule.apply(tax, pattern)
                 if tax_ids:
@@ -543,11 +579,7 @@ class Work(Effort, Progress, Timesheet, metaclass=PoolMeta):
 
     def _get_lines_to_invoice(self):
         if self.quantity_to_invoice:
-            if not self.product:
-                raise InvoicingError(
-                    gettext('project_invoice.msg_missing_product',
-                        work=self.rec_name))
-            elif self.invoice_unit_price is None:
+            if self.invoice_unit_price is None:
                 raise InvoicingError(
                     gettext('project_invoice.msg_missing_list_price',
                         work=self.rec_name))
@@ -570,7 +602,10 @@ class Work(Effort, Progress, Timesheet, metaclass=PoolMeta):
         pool = Pool()
         ModelData = pool.get('ir.model.data')
         Uom = pool.get('product.uom')
-        return Uom(ModelData.get_id('product', 'uom_hour'))
+        if self.price_list_hour:
+            return Uom(ModelData.get_id('product', 'uom_hour'))
+        elif self.product:
+            return self.product.default_uom
 
     def get_origins_to_invoice(self):
         return super().get_origins_to_invoice()
diff --git a/tests/scenario_project_invoice_effort.rst b/tests/scenario_project_invoice_effort.rst
index f1fb8891c8..d8306dbd06 100644
--- a/tests/scenario_project_invoice_effort.rst
+++ b/tests/scenario_project_invoice_effort.rst
@@ -87,10 +87,11 @@ Create account category::
     >>> account_category.account_revenue = revenue
     >>> account_category.save()
 
-Create product::
+Create products::
 
     >>> ProductUom = Model.get('product.uom')
     >>> hour, = ProductUom.find([('name', '=', 'Hour')])
+    >>> unit, = ProductUom.find([('name', '=', 'Unit')])
     >>> ProductTemplate = Model.get('product.template')
 
     >>> template = ProductTemplate()
@@ -102,6 +103,15 @@ Create product::
     >>> template.save()
     >>> product, = template.products
 
+    >>> template = ProductTemplate()
+    >>> template.name = 'Service Fixed'
+    >>> template.default_uom = unit
+    >>> template.type = 'service'
+    >>> template.list_price = Decimal('50')
+    >>> template.account_category = account_category
+    >>> template.save()
+    >>> product_fixed, = template.products
+
 Create a Project::
 
     >>> set_user(project_user)
@@ -122,8 +132,13 @@ Create a Project::
     >>> task_no_effort.name = "Task 2"
     >>> task_no_effort.type = 'task'
     >>> task_no_effort.effort_duration = None
+    >>> task_fixed = project.children.new()
+    >>> task_fixed.name = "Task 2"
+    >>> task_fixed.type = 'task'
+    >>> task_fixed.effort_duration = datetime.timedelta(hours=2)
+    >>> task_fixed.product = product_fixed
     >>> project.save()
-    >>> task, task_no_effort = project.children
+    >>> task, task_no_effort, task_fixed = project.children
 
 Check project amounts::
 
@@ -160,6 +175,8 @@ Do project::
     >>> set_user(project_user)
     >>> task_no_effort.progress = 1
     >>> task_no_effort.save()
+    >>> task_fixed.progress = 1
+    >>> task_fixed.save()
     >>> project.progress = 1
     >>> project.save()
 
@@ -167,7 +184,7 @@ Check project amounts::
 
     >>> project.reload()
     >>> project.amount_to_invoice
-    Decimal('20.00')
+    Decimal('70.00')
     >>> project.invoiced_amount
     Decimal('100.00')
 
@@ -178,4 +195,4 @@ Invoice again project::
     >>> project.amount_to_invoice
     Decimal('0.00')
     >>> project.invoiced_amount
-    Decimal('120.00')
+    Decimal('170.00')
diff --git a/tests/scenario_project_invoice_progress.rst b/tests/scenario_project_invoice_progress.rst
index 4be7e14b2d..a8af65b887 100644
--- a/tests/scenario_project_invoice_progress.rst
+++ b/tests/scenario_project_invoice_progress.rst
@@ -91,6 +91,10 @@ Create product::
 
     >>> ProductUom = Model.get('product.uom')
     >>> hour, = ProductUom.find([('name', '=', 'Hour')])
+    >>> unit, = ProductUom.find([('name', '=', 'Unit')])
+    >>> unit.rounding = 0.01
+    >>> unit.digits = 2
+    >>> unit.save()
     >>> ProductTemplate = Model.get('product.template')
 
     >>> template = ProductTemplate()
@@ -102,6 +106,15 @@ Create product::
     >>> template.save()
     >>> product, = template.products
 
+    >>> template = ProductTemplate()
+    >>> template.name = 'Service Fixed'
+    >>> template.default_uom = unit
+    >>> template.type = 'service'
+    >>> template.list_price = Decimal('50')
+    >>> template.account_category = account_category
+    >>> template.save()
+    >>> product_fixed, = template.products
+
 Create a Project::
 
     >>> set_user(project_user)
@@ -114,14 +127,18 @@ Create a Project::
     >>> project.project_invoice_method = 'progress'
     >>> project.product = product
     >>> project.effort_duration = datetime.timedelta(hours=1)
-    >>> task = ProjectWork()
+    >>> task = project.children.new()
     >>> task.name = 'Task 1'
     >>> task.type = 'task'
     >>> task.product = product
     >>> task.effort_duration = datetime.timedelta(hours=5)
-    >>> project.children.append(task)
+    >>> task_fixed = project.children.new()
+    >>> task_fixed.name = 'Task 2'
+    >>> task_fixed.type = 'task'
+    >>> task_fixed.product = product
+    >>> task_fixed.product = product_fixed
     >>> project.save()
-    >>> task, = project.children
+    >>> task, task_fixed = project.children
 
 Check project amounts::
 
@@ -135,12 +152,14 @@ Do 50% of task::
 
     >>> task.progress = 0.5
     >>> task.save()
+    >>> task_fixed.progress = 0.5
+    >>> task_fixed.save()
 
 Check project amounts::
 
     >>> project.reload()
     >>> project.amount_to_invoice
-    Decimal('50.00')
+    Decimal('75.00')
     >>> project.invoiced_amount
     Decimal('0.00')
 
@@ -151,13 +170,15 @@ Invoice project::
     >>> project.amount_to_invoice
     Decimal('0.00')
     >>> project.invoiced_amount
-    Decimal('50.00')
+    Decimal('75.00')
 
-Do 75% of task and 80% of project::
+Do 75% and 90% of tasks and 80% of project::
 
     >>> set_user(project_user)
     >>> task.progress = 0.75
     >>> task.save()
+    >>> task_fixed.progress = 0.9
+    >>> task_fixed.save()
     >>> project.progress = 0.80
     >>> project.save()
 
@@ -165,9 +186,9 @@ Check project amounts::
 
     >>> project.reload()
     >>> project.amount_to_invoice
-    Decimal('41.00')
+    Decimal('61.00')
     >>> project.invoiced_amount
-    Decimal('50.00')
+    Decimal('75.00')
 
 Invoice again project::
 
@@ -176,4 +197,4 @@ Invoice again project::
     >>> project.amount_to_invoice
     Decimal('0.00')
     >>> project.invoiced_amount
-    Decimal('91.00')
+    Decimal('136.00')
diff --git a/tryton.cfg b/tryton.cfg
index b63779f9cf..b09a7cf9ec 100644
--- a/tryton.cfg
+++ b/tryton.cfg
@@ -7,6 +7,7 @@ depends:
     timesheet
     account
     account_invoice
+    account_product
     product
 xml:
     project.xml